The present invention relates, in general, to electronics, and more particularly, to semiconductors, structures thereof, and methods of forming semiconductor devices.
In the past, the semiconductor industry utilized various methods and structures to form power supply controllers that regulated an output voltage to a desired value. Some advantages features of those power supply controllers included a method to detect an over-temperature condition of the ambient environment of the power supply controller and a method to detect an over-voltage condition of the input voltage used for operating the power supply controller. In order to detect these two different conditions, the power supply controller generally used two respective inputs. Using two inputs resulted in using two terminals of a semiconductor package for these two conditions. Due to the limited number of terminals on a semiconductor package, using two terminals for the two different operating conditions often prevented incorporating other features into the power supply controller.
Additionally, the two different conditions generally were detected by monitoring a change in a voltage that represented the condition. The various circuits required to detect the voltage condition resulted in inaccuracies.
Accordingly, it is desirable to have a power supply controller that can detect an over-voltage and an over-temperature condition on a single input of the power supply controller, and that more accurately detects the two conditions.
For simplicity and clarity of the illustration, elements in the figures are not necessarily to scale, and the same reference numbers in different figures denote the same elements. Additionally, descriptions and details of well-known steps and elements are omitted for simplicity of the description. As used herein current carrying electrode means an element of a device that carries current through the device such as a source or a drain of an MOS transistor or an emitter or a collector of a bipolar transistor or a cathode or anode of a diode, and a control electrode means an element of the device that controls current through the device such as a gate of an MOS transistor or a base of a bipolar transistor. Although the devices are explained herein as certain N-channel or P-Channel devices, or certain N-type or P-type doped regions, a person of ordinary skill in the art will appreciate that complementary devices are also possible in accordance with the present invention. It will be appreciated by those skilled in the art that the words during, while, and when as used herein relating to circuit operation are not exact terms that mean an action takes place instantly upon an initiating action but that there may be some small but reasonable delay, such as a propagation delay, between the reaction that is initiated by the initial action. The use of the word approximately or substantially means that a value of an element has a parameter that is expected to be very close to a stated value or position. However, as is well known in the art there are always minor variances that prevent the values or positions from being exactly as stated. It is well established in the art that variances of up to at least ten per cent (10%) (and up to twenty per cent (20%) for semiconductor doping concentrations) are reasonable variances from the ideal goal of exactly as described.